Micrometer-gage



(No Model.)

J. MOFFITT.

MIGROMETBR GAGE.

No. 369,357. Patented Sept. 6, 1887.

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nA PETERS, Fnnmnmgupm, wwwrun@ c ing-sleevcat lineyy, Fig. 5.

Nrrnn STATES PATENT Darren.

JERREY MOFFITT, 0F SOUTHBRIDGE, MASSACHUSETTS.

MlCROlVlETER-GAG.

SPECIFICATION forming part of Letters Patent No. 369,357, datedSeptember 6, 1887.

Scrl-al No. 233,531. (No model.)

fo all whom it may concern,.-

Be it known that I, JERREY Monnier, a citizen of the United States,residing at Southbridge, in thc county of .Vorcester and State ofMassachusetts, have invented certain new and useful Improvements inMiorometer-Calipers, of which the following, together with theaccompanying drawings, is a specification sufficiently full, clear, andexact to enable persons skilled in the art to which this inventionappertains to make and use the same.

`The'object of my present invention is to provide an adjusting devicefor the micrometerscrew which will overcome the objection heretoforefound to the irregular wearing of the screw and the binding or crampingof the threads after the screw has been turned beyond the limit or pointof its usual wear; also, to provide a practical adjusting deviceconveniently accessi ble for adjustment without the necessity ofremoving the outer sleeve and micrometer-*screw from the frame. Theseobjects I attain by an instrument constructed as shown in the drawingsand as hereinafter described, the particular subject-matter claimedbeing hereinafter definitely specied.

ln the drawings, Figure l is a side view of a micrometer-caliperconstructed in accordance with my invention. Fig. 2 is a section showingthe foot of the frame and the anvil or stud. Fig. 31's a section at line.t a', Fig. 1, looking upward. Fig. 4 is a section of the frame atlinear a', with the other parts removed, looking downward. Fig. 5 is aside view of the adj listing-sleeve separate from the frame. 6 is atransverse section of the adjust Fig. 7 is a transverse section at theposition of linee e, Fig. 1.

In referring to parts, A denotes the frame, which is provided with theprojecting cylinder A', through which the micrometer screw or spindle Bpasses, and with a foot, a, for the anvilstud. Y

C indicates the outer sleeve or cylinder, iixed to the head of themicrometer screw or spindle B, and provided with a milled head, by whichit can-be conveniently turned for rotating said screw and effectingadjustment of the caliper. The cylinderA and the outer sleeve, C, areprovided with a graduated scale 'for indicating the measurements in theusual manner.

D indicates an adj ustingsleeve for the purpose of taking up backlashand wear of the screwthread- Said adj usting-sleevc is made, asindicated in Fig. 5, with a screw-thread, d, at its inner end, thatmatches with a corre sponding thread, d', formed at the inner end of theframe-cylinder, while within the opposite end of said adj listing-sleevethere is formed the screwthread b', that matches with the screwthread bon the micrometer screw or spindle B. The sleeve D is also provided withthe inclined or conical section f, that engages with a shoulder oropposite incline, c, formed within the framecylinder A when the partsare together.

The screw-threads d d for the adjustingsleeve and the screw-threads Z) bfor the niicrometcr-screw are made of ,the same pitch* say forty to theinch-so that any adjustment or movement of the sleeve will not causederangement of the graduated index, as the movement on one thread willcompensate for the movement on the other when the sleeveD is revolvedfor effecting the adjustment. The sleeve D is slittcd throughout thegreater portion of its length, as indicated at m, (see Figs. 5 and 6,)and is provided at its inner end, D', with a nick, a, to facilitateturning it when inserted in the frame.

Vhen the sleeve D is rotated, the action of the screw-threads d d drawsdown the incline or coned surfacef against the inclined surface e, andsaid surface f acts as a wedge for forcing together the outer ends ofthe slittcd sleeve D, causing the screw-thread b to more closely embracethe thread b of the micrometer-screw, the pressure being elastic byreason of the springing action of thc sides of the slittcd sleeve.

The sleeve D can be turned at any time for tightening or loosening thebearing upon the thread b by a suitable spanner or wrench applied to theend of the sleeve DWhere it projects from the frame, the adjustmentbeing conveniently effected without the necessity of unscrewing thecap-cylinder G or removing the micrometer-screw from its place.

This manner of constructing the adjustingsleeve and adjacent parts iscomparatively simple and convenient for manufacture. Another advantageis, that it leaves no opening or crevice in the exterior of theinstrument to ICO become filled 'with dirt or grit and thereby interferewith the perfect operation of the instrument. This manner ofconstructing the sleeve and arranging the same in combination with theframe and micrometerscrew is a feature of my invention.

The end or foot of the frame at ce, I make of the same thickness as thediameter of the micrometer-screw B, and with its outer part rounded offon a circle corresponding to the cylindrical circle of the screw. Intosaid end a of the frame I insert the anvil or step I in the mannershown. Saidl anvil has a squarefaced head corresponding in size to themicrometer-screw, and a screw-threaded shank, I', of smaller diameter,that is screwed into a threaded hole,-I2, formed through the foot a ofthe frame, the anvil-shank I being inserted therethrough in outwarddirection, and its outer end provided with a nick or means whereby thescrew can be turned for adjusting the anvil.

The face of the anvil and micrometer-screw arey made the full diameteror area of the screw, so as to give square angles, as attI i. By thusforming the end of the frame A, the anvil-top, and end of the micrometerscrew of the same diameter I produce an instrument which can be used forcalipering the gage of slightly projecting ribs or flanges on thesurface of solid bodies, since the square anglesz' and the nonprojectionof the frame at a beyond the circumference of the anvil and screwpermits of the caliper being worked close down to a flat surface, asindicated in dotted line, Fig. 3.

I am aware that micrometer-calipers have heretofore been made in whichdevices for taking up the vwear on the screw-threads are employed, andIdo nottherefore claim ,broadly, the employment of means for adjustment;but,

so far as I am aware, the means which I employ are different inconstruction and mode of operation from any devices heretofore employedfor the purpose, while my device also gives elastic pressure on thethreads of the micrometer-screw, which is a desirable incidentalfeature.

What I claim as of my invention, and desire to secure by Letters Patent,is

l. The combination, with the frame having the projecting cylinderprovided internally with an inclined or conical surface and ascrewthread at thc inner end, the micrometer-screw, and the outersleeve, of the internally-slitted adj usting-sleeve having an externalthread, d, at its inner end fitting to a thread in the frame, auinternal thread, b', at its outer end fitting the micrometer-screw, andan intermediate conical surface, f, engaging the conical snrface e ofthecylinder, substantially as set forth.

2. The combination, with the micrometerscrew B, its supporting-cylinderA, and operating-sleeve C, of the adjusting-sleeve D, having an inclinedsurface and engaging threads, with its end D extending from thesupporting-cylinder in convenient position to be turned by a wrench orSpanner, substantially as set forth.

Witness my hand this 28th day of March, A. D. 1887.

JERREY MOFFITT. Witnesses:

E. M. PHILLIrs, WM. T. RoBrNsoN.

